A composition formed from a calcium or magnesium carbonate-comprising material and a surface-treatment composition comprising at least one cross-linkable compound

Abstract

A composition formed from a calcium or magnesium carbonate-including material and a surface-treatment composition including at least one cross-linkable compound, a dry process for the preparation of such a composition, a curable elastomer mixture comprising an elastomer resin and the composition, a cured elastomer product formed from the curable elastomer mixture, a process for preparing the cured elastomer product, the use of at least one cross-linkable compound including at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-including material in the compounding of an elastomer formed from an elastomer resin and at least one calcium or magnesium carbonate-comprising material as filler as well as an article formed from the cured elastomer product.

1 . A composition formed from a calcium or magnesium carbonate-comprising material selected from among sedimentary ground calcium carbonate, precipitated calcium carbonate, surface-reacted calcium carbonate, precipitated hydromagnesite and mixtures thereof, and from 0.5 to 20 wt.-%, based on the total weight of the calcium or magnesium carbonate-comprising material, of a surface-treatment composition comprising at least one cross-linkable compound comprising at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-comprising material. 
     
     
         2 . The composition according to  claim 1 , wherein the sedimentary ground calcium carbonate is selected from the group consisting of marble, limestone, dolomite, chalk and mixtures thereof, or the precipitated calcium carbonate is selected from the group consisting of the aragonitic, vateritic and calcitic mineralogical crystal forms, colloidal precipitated calcium carbonate, and mixtures thereof. 
     
     
         3 . The composition according to  claim 1 , wherein the calcium carbonate-comprising material is sedimentary ground calcium carbonate and/or precipitated calcium carbonate and has
 i) a weight median particle size d 50  value measured by the sedimentation method in the range from 0.1 μm to 10 μm, and/or   ii) a top cut (d 98 ) measured by the sedimentation method of ≤45 μm, and/or   iii) a specific surface area (BET) of from 0.5 to 150 m 2 /g as measured using nitrogen and the BET method according to ISO 9277:2010, and/or   iv) a residual total moisture content of ≤2 wt.-%, based on the total dry weight of the at least one calcium carbonate-comprising material.   
     
     
         4 . The composition according to  claim 1 , wherein the calcium carbonate-comprising material is surface-reacted calcium carbonate being a reaction product of (sedimentary) ground calcium carbonate or precipitated calcium carbonate with carbon dioxide and one or more H 3 O +  ion donors, wherein the carbon dioxide is formed in situ by the H 3 O +  ion donors treatment and/or is supplied from an external source or the magnesium carbonate-comprising material is precipitated hydromagnesite and has
 i) a volume median particle size d 50  from 0.1 to 75 μm, and/or 
 ii) a volume top cut particle size d 98  from 0.2 to μm, and/or 
 iii) a specific surface area of from 15 m 2 /g to 200 m 2 /g, measured using nitrogen and the BET method. 
 
     
     
         5 . The composition according to  claim 1 , wherein the at least one functional group that is suitable for reacting with the calcium or magnesium carbonate-comprising material of the cross-linkable compound comprises one or more terminal triethoxysilyl, trimethoxysilyl and/or organic acid anhydride and/or salts thereof and/or carboxylic acid group(s) and/or salts thereof. 
     
     
         6 . The composition according to  claim 1 , wherein the cross-linkable compound is at least one grafted polymer comprising at least one succinic anhydride group obtained by grafting maleic anhydride onto a homo- or copolymer comprising butadiene units and optionally styrene units or a sulfur-containing trialkoxysilane. 
     
     
         7 . The composition according to  claim 6 , wherein the at least one grafted polymer is
 a) a grafted polybutadiene homopolymer comprising at least one succinic anhydride group obtained by grafting maleic anhydride onto a polybutadiene homopolymer and having
 i) a number average molecular weight Mn measured by gel permeation chromatography from 1,000 to 20,000 g/mol, and/or 
 ii) a number of functional groups per chain in the range from 2 to 12, and/or 
 iii) an anhydride equivalent weight in the range from 400 to 2,200, 
   
       or
 b) a grafted polybutadiene-styrene copolymer comprising at least one succinic anhydride group obtained by grafting maleic anhydride onto a polybutadiene-styrene copolymer and having a 1,2 vinyl content from 20 to 80 mol.-%, based on the total weight of the grafted polybutadiene-styrene copolymer. 
 
     
     
         8 . The composition according to  claim 1 , wherein the composition is formed in that the at least one calcium or magnesium carbonate-comprising material and the at least one cross-linkable compound are provided as physical mixture and/or in that the at least one calcium or magnesium carbonate-comprising material is contacted with the at least one cross-linkable compound such that a treatment layer comprising the at least one cross-linkable compound and/or salty reaction products thereof is formed on the surface of the at least one calcium or magnesium carbonate-comprising material. 
     
     
         9 . The composition according to  claim 1 , wherein the surface-treatment composition comprises at least one further surface-treatment agent selected from the group consisting of
 I) a phosphoric acid ester blend of one or more phosphoric acid mono ester and/or salts thereof and/or one or more phosphoric acid di-ester and/or salts thereof, and/or   II) at least one saturated or unsaturated aliphatic linear or branched carboxylic acid and/or salts thereof and/or   III) at least one mono-substituted succinic anhydride consisting of succinic anhydride mono-substituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from at least C2 to C30 in the substituent and/or salts thereof, and/or   IV) at least one polydialkylsiloxane, and   V) mixtures of one or more materials according to I) to IV).   
     
     
         10 . A dry process for the preparation of a composition according to  claim 1 , the process comprises at least the steps of:
 a) providing a calcium or magnesium carbonate-comprising material selected from among sedimentary ground calcium carbonate, precipitated calcium carbonate, surface-reacted calcium carbonate, precipitated hydromagnesite and mixtures thereof;   b) providing at least one cross-linkable compound comprising at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-comprising material in an amount from 0.1 to 10 mg/m 2 , based on the total weight of the calcium or magnesium carbonate-comprising material,   c) optionally providing at least one further surface-treatment agent selected from the group consisting of:
 I) a phosphoric acid ester blend of one or more phosphoric acid mono ester and/or salts thereof and/or one or more phosphoric acid di-ester and/or salts thereof, and/or 
 II) at least one saturated or unsaturated aliphatic linear or branched carboxylic acid and/or salts thereof and/or 
 III) at least one mono-substituted succinic anhydride consisting of succinic anhydride mono-substituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from at least C2 to C30 in the substituent and/or salts thereof, and/or 
 IV) at least one polydialkylsiloxane, and 
 V) mixtures of one or more materials according to I) to IV), 
   d) optionally heating the at least one cross-linkable compound, and   e) contacting the calcium or magnesium carbonate-comprising material under mixing, in one or more steps, with the at least one cross-linkable compound,   f) if present, heating the at least one further surface-treatment agent to its melting point or above such that a molten surface-treatment agent is obtained and contacting the calcium or magnesium carbonate-comprising material under mixing, in one or more steps, with the molten surface-treatment agent simultaneously or subsequently to the at least one cross-linkable compound.   
     
     
         11 . A curable elastomer mixture comprising
 a) an elastomer resin, and   b) from 5 to 300 wt.-%, based on the total weight of the elastomer resin, of the composition according to  claim 1 ,   wherein the composition is dispersed in the elastomer resin.   
     
     
         12 . The curable elastomer mixture according to  claim 11 , wherein the elastomer resin is selected from natural or synthetic rubber. 
     
     
         13 . The curable elastomer mixture according to  claim 11 , wherein the mixture further comprises additives. 
     
     
         14 . A cured elastomer product formed from the curable elastomer mixture of a  claim 11 . 
     
     
         15 . A process for preparing a cured elastomer product as defined in  claim 14 , wherein the process comprises the steps of
 a) providing an elastomer resin,   b) providing from 5 to 300 wt.-%, based on the total weight of the elastomer resin, of at least one calcium or magnesium carbonate-comprising material as filler,   c) providing from 0.1 to 10 mg/m 2 , based on the total weight of the calcium or magnesium carbonate-comprising material, of at least one cross-linkable compound comprising at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-comprising material,   d) optionally providing at least one further surface-treatment agent selected from the group consisting of
 I) a phosphoric acid ester blend of one or more phosphoric acid mono ester and/or salts thereof and/or one or more phosphoric acid di-ester and/or salts thereof, and/or 
 II) at least one saturated or unsaturated aliphatic linear or branched carboxylic acid and/or salts thereof and/or 
 III) at least one mono-substituted succinic anhydride consisting of succinic anhydride mono-substituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from at least C2 to C30 in the substituent and/or salts thereof, and/or 
 IV) at least one polydialkylsiloxane, and 
 V) mixtures of one or more materials according to I) to IV), 
   e) optionally providing further additives additives,   f) contacting the components of step a), step b), step c) and optionally step d) and step e) in any order, and   g) curing the mixture obtained in step f) such that a cured elastomer product is formed.   
     
     
         16 . The process according to  claim 15 , wherein in contacting step f) firstly the at least one calcium or magnesium carbonate-comprising material of step b) is contacted under mixing, in one or more steps, with the at least one cross-linkable compound of step c) and, if present, subsequently or simultaneously, with the at least one further surface-treatment agent of step d) such that a surface treatment layer comprising the at least one cross-linkable compound and/or salty reaction product(s) thereof and optionally the at least one further surface-treatment agent and/or salty reaction product(s) thereof is/are formed on the surface of said at least one calcium or magnesium carbonate-comprising material of step b), and secondly this surface-treated calcium or magnesium carbonate-comprising material is contacted under mixing, in one or more steps, with the elastomer resin of step a). 
     
     
         17 . The process according to  claim 16 , wherein the further additives of step e) are contacted under mixing, in one or more steps, with the surface-treated calcium or magnesium carbonate-comprising material before or after, the surface-treated calcium or magnesium carbonate-comprising material is contacted under mixing, in one or more steps, with the elastomer resin of step a). 
     
     
         18 . The process according to  claim 15 , wherein contacting step f) is carried out during curing step g) in that the at least one cross-linkable compound is contacted under mixing with the elastomer resin of step a) before or after adding the at least one calcium or magnesium carbonate-comprising material. 
     
     
         19 . A method comprising compounding an elastomer formed from an elastomer resin and at least one calcium or magnesium carbonate-comprising material as filler with at least one cross-linkable compound comprising at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-comprising material, to increase the mechanical properties of such a compounded elastomer in comparison to the same elastomer formed from the same elastomer resin and at least one calcium or magnesium carbonate-comprising material but without the at least one cross-linkable compound comprising at least two functional groups, wherein at least one functional group is suitable for cross-linking an elastomer resin and wherein at least one functional group is suitable for reacting with the calcium or magnesium carbonate-comprising material. 
     
     
         20 . An article formed from a cured elastomer product according to  claim 14 , wherein the article is selected from the group comprising tubeless articles, membranes, sealings, gloves, pipes, cable, electrical connectors, oil hoses, shoe soles, O-ring seals, shaft seals, gaskets, tubing, valve stem seals, fuel hose, tank seals, diaphragms, flexi liners for pumps, mechanical seals, pipe coupling, valve lines, military flare blinders, electrical connectors, fuel joints, roll covers, firewall seals, clips for jet engines, and the like.